xref: /openbmc/linux/drivers/net/ethernet/intel/igb/e1000_mbx.c (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Intel(R) Gigabit Ethernet Linux driver
3  * Copyright(c) 2007-2014 Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program; if not, see <http://www.gnu.org/licenses/>.
16  *
17  * The full GNU General Public License is included in this distribution in
18  * the file called "COPYING".
19  *
20  * Contact Information:
21  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
22  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
23  */
24 
25 #include "e1000_mbx.h"
26 
27 /**
28  *  igb_read_mbx - Reads a message from the mailbox
29  *  @hw: pointer to the HW structure
30  *  @msg: The message buffer
31  *  @size: Length of buffer
32  *  @mbx_id: id of mailbox to read
33  *
34  *  returns SUCCESS if it successfully read message from buffer
35  **/
36 s32 igb_read_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id,
37 		 bool unlock)
38 {
39 	struct e1000_mbx_info *mbx = &hw->mbx;
40 	s32 ret_val = -E1000_ERR_MBX;
41 
42 	/* limit read to size of mailbox */
43 	if (size > mbx->size)
44 		size = mbx->size;
45 
46 	if (mbx->ops.read)
47 		ret_val = mbx->ops.read(hw, msg, size, mbx_id, unlock);
48 
49 	return ret_val;
50 }
51 
52 /**
53  *  igb_write_mbx - Write a message to the mailbox
54  *  @hw: pointer to the HW structure
55  *  @msg: The message buffer
56  *  @size: Length of buffer
57  *  @mbx_id: id of mailbox to write
58  *
59  *  returns SUCCESS if it successfully copied message into the buffer
60  **/
61 s32 igb_write_mbx(struct e1000_hw *hw, u32 *msg, u16 size, u16 mbx_id)
62 {
63 	struct e1000_mbx_info *mbx = &hw->mbx;
64 	s32 ret_val = 0;
65 
66 	if (size > mbx->size)
67 		ret_val = -E1000_ERR_MBX;
68 
69 	else if (mbx->ops.write)
70 		ret_val = mbx->ops.write(hw, msg, size, mbx_id);
71 
72 	return ret_val;
73 }
74 
75 /**
76  *  igb_check_for_msg - checks to see if someone sent us mail
77  *  @hw: pointer to the HW structure
78  *  @mbx_id: id of mailbox to check
79  *
80  *  returns SUCCESS if the Status bit was found or else ERR_MBX
81  **/
82 s32 igb_check_for_msg(struct e1000_hw *hw, u16 mbx_id)
83 {
84 	struct e1000_mbx_info *mbx = &hw->mbx;
85 	s32 ret_val = -E1000_ERR_MBX;
86 
87 	if (mbx->ops.check_for_msg)
88 		ret_val = mbx->ops.check_for_msg(hw, mbx_id);
89 
90 	return ret_val;
91 }
92 
93 /**
94  *  igb_check_for_ack - checks to see if someone sent us ACK
95  *  @hw: pointer to the HW structure
96  *  @mbx_id: id of mailbox to check
97  *
98  *  returns SUCCESS if the Status bit was found or else ERR_MBX
99  **/
100 s32 igb_check_for_ack(struct e1000_hw *hw, u16 mbx_id)
101 {
102 	struct e1000_mbx_info *mbx = &hw->mbx;
103 	s32 ret_val = -E1000_ERR_MBX;
104 
105 	if (mbx->ops.check_for_ack)
106 		ret_val = mbx->ops.check_for_ack(hw, mbx_id);
107 
108 	return ret_val;
109 }
110 
111 /**
112  *  igb_check_for_rst - checks to see if other side has reset
113  *  @hw: pointer to the HW structure
114  *  @mbx_id: id of mailbox to check
115  *
116  *  returns SUCCESS if the Status bit was found or else ERR_MBX
117  **/
118 s32 igb_check_for_rst(struct e1000_hw *hw, u16 mbx_id)
119 {
120 	struct e1000_mbx_info *mbx = &hw->mbx;
121 	s32 ret_val = -E1000_ERR_MBX;
122 
123 	if (mbx->ops.check_for_rst)
124 		ret_val = mbx->ops.check_for_rst(hw, mbx_id);
125 
126 	return ret_val;
127 }
128 
129 /**
130  *  igb_unlock_mbx - unlock the mailbox
131  *  @hw: pointer to the HW structure
132  *  @mbx_id: id of mailbox to check
133  *
134  *  returns SUCCESS if the mailbox was unlocked or else ERR_MBX
135  **/
136 s32 igb_unlock_mbx(struct e1000_hw *hw, u16 mbx_id)
137 {
138 	struct e1000_mbx_info *mbx = &hw->mbx;
139 	s32 ret_val = -E1000_ERR_MBX;
140 
141 	if (mbx->ops.unlock)
142 		ret_val = mbx->ops.unlock(hw, mbx_id);
143 
144 	return ret_val;
145 }
146 
147 /**
148  *  igb_poll_for_msg - Wait for message notification
149  *  @hw: pointer to the HW structure
150  *  @mbx_id: id of mailbox to write
151  *
152  *  returns SUCCESS if it successfully received a message notification
153  **/
154 static s32 igb_poll_for_msg(struct e1000_hw *hw, u16 mbx_id)
155 {
156 	struct e1000_mbx_info *mbx = &hw->mbx;
157 	int countdown = mbx->timeout;
158 
159 	if (!countdown || !mbx->ops.check_for_msg)
160 		goto out;
161 
162 	while (countdown && mbx->ops.check_for_msg(hw, mbx_id)) {
163 		countdown--;
164 		if (!countdown)
165 			break;
166 		udelay(mbx->usec_delay);
167 	}
168 
169 	/* if we failed, all future posted messages fail until reset */
170 	if (!countdown)
171 		mbx->timeout = 0;
172 out:
173 	return countdown ? 0 : -E1000_ERR_MBX;
174 }
175 
176 /**
177  *  igb_poll_for_ack - Wait for message acknowledgement
178  *  @hw: pointer to the HW structure
179  *  @mbx_id: id of mailbox to write
180  *
181  *  returns SUCCESS if it successfully received a message acknowledgement
182  **/
183 static s32 igb_poll_for_ack(struct e1000_hw *hw, u16 mbx_id)
184 {
185 	struct e1000_mbx_info *mbx = &hw->mbx;
186 	int countdown = mbx->timeout;
187 
188 	if (!countdown || !mbx->ops.check_for_ack)
189 		goto out;
190 
191 	while (countdown && mbx->ops.check_for_ack(hw, mbx_id)) {
192 		countdown--;
193 		if (!countdown)
194 			break;
195 		udelay(mbx->usec_delay);
196 	}
197 
198 	/* if we failed, all future posted messages fail until reset */
199 	if (!countdown)
200 		mbx->timeout = 0;
201 out:
202 	return countdown ? 0 : -E1000_ERR_MBX;
203 }
204 
205 /**
206  *  igb_read_posted_mbx - Wait for message notification and receive message
207  *  @hw: pointer to the HW structure
208  *  @msg: The message buffer
209  *  @size: Length of buffer
210  *  @mbx_id: id of mailbox to write
211  *
212  *  returns SUCCESS if it successfully received a message notification and
213  *  copied it into the receive buffer.
214  **/
215 static s32 igb_read_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
216 			       u16 mbx_id)
217 {
218 	struct e1000_mbx_info *mbx = &hw->mbx;
219 	s32 ret_val = -E1000_ERR_MBX;
220 
221 	if (!mbx->ops.read)
222 		goto out;
223 
224 	ret_val = igb_poll_for_msg(hw, mbx_id);
225 
226 	if (!ret_val)
227 		ret_val = mbx->ops.read(hw, msg, size, mbx_id, true);
228 out:
229 	return ret_val;
230 }
231 
232 /**
233  *  igb_write_posted_mbx - Write a message to the mailbox, wait for ack
234  *  @hw: pointer to the HW structure
235  *  @msg: The message buffer
236  *  @size: Length of buffer
237  *  @mbx_id: id of mailbox to write
238  *
239  *  returns SUCCESS if it successfully copied message into the buffer and
240  *  received an ack to that message within delay * timeout period
241  **/
242 static s32 igb_write_posted_mbx(struct e1000_hw *hw, u32 *msg, u16 size,
243 				u16 mbx_id)
244 {
245 	struct e1000_mbx_info *mbx = &hw->mbx;
246 	s32 ret_val = -E1000_ERR_MBX;
247 
248 	/* exit if either we can't write or there isn't a defined timeout */
249 	if (!mbx->ops.write || !mbx->timeout)
250 		goto out;
251 
252 	/* send msg */
253 	ret_val = mbx->ops.write(hw, msg, size, mbx_id);
254 
255 	/* if msg sent wait until we receive an ack */
256 	if (!ret_val)
257 		ret_val = igb_poll_for_ack(hw, mbx_id);
258 out:
259 	return ret_val;
260 }
261 
262 static s32 igb_check_for_bit_pf(struct e1000_hw *hw, u32 mask)
263 {
264 	u32 mbvficr = rd32(E1000_MBVFICR);
265 	s32 ret_val = -E1000_ERR_MBX;
266 
267 	if (mbvficr & mask) {
268 		ret_val = 0;
269 		wr32(E1000_MBVFICR, mask);
270 	}
271 
272 	return ret_val;
273 }
274 
275 /**
276  *  igb_check_for_msg_pf - checks to see if the VF has sent mail
277  *  @hw: pointer to the HW structure
278  *  @vf_number: the VF index
279  *
280  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
281  **/
282 static s32 igb_check_for_msg_pf(struct e1000_hw *hw, u16 vf_number)
283 {
284 	s32 ret_val = -E1000_ERR_MBX;
285 
286 	if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFREQ_VF1 << vf_number)) {
287 		ret_val = 0;
288 		hw->mbx.stats.reqs++;
289 	}
290 
291 	return ret_val;
292 }
293 
294 /**
295  *  igb_check_for_ack_pf - checks to see if the VF has ACKed
296  *  @hw: pointer to the HW structure
297  *  @vf_number: the VF index
298  *
299  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
300  **/
301 static s32 igb_check_for_ack_pf(struct e1000_hw *hw, u16 vf_number)
302 {
303 	s32 ret_val = -E1000_ERR_MBX;
304 
305 	if (!igb_check_for_bit_pf(hw, E1000_MBVFICR_VFACK_VF1 << vf_number)) {
306 		ret_val = 0;
307 		hw->mbx.stats.acks++;
308 	}
309 
310 	return ret_val;
311 }
312 
313 /**
314  *  igb_check_for_rst_pf - checks to see if the VF has reset
315  *  @hw: pointer to the HW structure
316  *  @vf_number: the VF index
317  *
318  *  returns SUCCESS if the VF has set the Status bit or else ERR_MBX
319  **/
320 static s32 igb_check_for_rst_pf(struct e1000_hw *hw, u16 vf_number)
321 {
322 	u32 vflre = rd32(E1000_VFLRE);
323 	s32 ret_val = -E1000_ERR_MBX;
324 
325 	if (vflre & BIT(vf_number)) {
326 		ret_val = 0;
327 		wr32(E1000_VFLRE, BIT(vf_number));
328 		hw->mbx.stats.rsts++;
329 	}
330 
331 	return ret_val;
332 }
333 
334 /**
335  *  igb_obtain_mbx_lock_pf - obtain mailbox lock
336  *  @hw: pointer to the HW structure
337  *  @vf_number: the VF index
338  *
339  *  return SUCCESS if we obtained the mailbox lock
340  **/
341 static s32 igb_obtain_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
342 {
343 	s32 ret_val = -E1000_ERR_MBX;
344 	u32 p2v_mailbox;
345 	int count = 10;
346 
347 	do {
348 		/* Take ownership of the buffer */
349 		wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_PFU);
350 
351 		/* reserve mailbox for vf use */
352 		p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
353 		if (p2v_mailbox & E1000_P2VMAILBOX_PFU) {
354 			ret_val = 0;
355 			break;
356 		}
357 		udelay(1000);
358 	} while (count-- > 0);
359 
360 	return ret_val;
361 }
362 
363 /**
364  *  igb_release_mbx_lock_pf - release mailbox lock
365  *  @hw: pointer to the HW structure
366  *  @vf_number: the VF index
367  *
368  *  return SUCCESS if we released the mailbox lock
369  **/
370 static s32 igb_release_mbx_lock_pf(struct e1000_hw *hw, u16 vf_number)
371 {
372 	u32 p2v_mailbox;
373 
374 	/* drop PF lock of mailbox, if set */
375 	p2v_mailbox = rd32(E1000_P2VMAILBOX(vf_number));
376 	if (p2v_mailbox & E1000_P2VMAILBOX_PFU)
377 		wr32(E1000_P2VMAILBOX(vf_number),
378 		     p2v_mailbox & ~E1000_P2VMAILBOX_PFU);
379 
380 	return 0;
381 }
382 
383 /**
384  *  igb_write_mbx_pf - Places a message in the mailbox
385  *  @hw: pointer to the HW structure
386  *  @msg: The message buffer
387  *  @size: Length of buffer
388  *  @vf_number: the VF index
389  *
390  *  returns SUCCESS if it successfully copied message into the buffer
391  **/
392 static s32 igb_write_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
393 			    u16 vf_number)
394 {
395 	s32 ret_val;
396 	u16 i;
397 
398 	/* lock the mailbox to prevent pf/vf race condition */
399 	ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
400 	if (ret_val)
401 		goto out_no_write;
402 
403 	/* flush msg and acks as we are overwriting the message buffer */
404 	igb_check_for_msg_pf(hw, vf_number);
405 	igb_check_for_ack_pf(hw, vf_number);
406 
407 	/* copy the caller specified message to the mailbox memory buffer */
408 	for (i = 0; i < size; i++)
409 		array_wr32(E1000_VMBMEM(vf_number), i, msg[i]);
410 
411 	/* Interrupt VF to tell it a message has been sent and release buffer*/
412 	wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_STS);
413 
414 	/* update stats */
415 	hw->mbx.stats.msgs_tx++;
416 
417 out_no_write:
418 	return ret_val;
419 
420 }
421 
422 /**
423  *  igb_read_mbx_pf - Read a message from the mailbox
424  *  @hw: pointer to the HW structure
425  *  @msg: The message buffer
426  *  @size: Length of buffer
427  *  @vf_number: the VF index
428  *  @unlock: unlock the mailbox when done?
429  *
430  *  This function copies a message from the mailbox buffer to the caller's
431  *  memory buffer.  The presumption is that the caller knows that there was
432  *  a message due to a VF request so no polling for message is needed.
433  **/
434 static s32 igb_read_mbx_pf(struct e1000_hw *hw, u32 *msg, u16 size,
435 			   u16 vf_number, bool unlock)
436 {
437 	s32 ret_val;
438 	u16 i;
439 
440 	/* lock the mailbox to prevent pf/vf race condition */
441 	ret_val = igb_obtain_mbx_lock_pf(hw, vf_number);
442 	if (ret_val)
443 		goto out_no_read;
444 
445 	/* copy the message to the mailbox memory buffer */
446 	for (i = 0; i < size; i++)
447 		msg[i] = array_rd32(E1000_VMBMEM(vf_number), i);
448 
449 	/* Acknowledge the message and release mailbox lock (or not) */
450 	if (unlock)
451 		wr32(E1000_P2VMAILBOX(vf_number), E1000_P2VMAILBOX_ACK);
452 	else
453 		wr32(E1000_P2VMAILBOX(vf_number),
454 		     E1000_P2VMAILBOX_ACK | E1000_P2VMAILBOX_PFU);
455 
456 	/* update stats */
457 	hw->mbx.stats.msgs_rx++;
458 
459 out_no_read:
460 	return ret_val;
461 }
462 
463 /**
464  *  e1000_init_mbx_params_pf - set initial values for pf mailbox
465  *  @hw: pointer to the HW structure
466  *
467  *  Initializes the hw->mbx struct to correct values for pf mailbox
468  */
469 s32 igb_init_mbx_params_pf(struct e1000_hw *hw)
470 {
471 	struct e1000_mbx_info *mbx = &hw->mbx;
472 
473 	mbx->timeout = 0;
474 	mbx->usec_delay = 0;
475 
476 	mbx->size = E1000_VFMAILBOX_SIZE;
477 
478 	mbx->ops.read = igb_read_mbx_pf;
479 	mbx->ops.write = igb_write_mbx_pf;
480 	mbx->ops.read_posted = igb_read_posted_mbx;
481 	mbx->ops.write_posted = igb_write_posted_mbx;
482 	mbx->ops.check_for_msg = igb_check_for_msg_pf;
483 	mbx->ops.check_for_ack = igb_check_for_ack_pf;
484 	mbx->ops.check_for_rst = igb_check_for_rst_pf;
485 	mbx->ops.unlock = igb_release_mbx_lock_pf;
486 
487 	mbx->stats.msgs_tx = 0;
488 	mbx->stats.msgs_rx = 0;
489 	mbx->stats.reqs = 0;
490 	mbx->stats.acks = 0;
491 	mbx->stats.rsts = 0;
492 
493 	return 0;
494 }
495 
496